He has worn the jerseys of three New Zealand provinces (Otago, North Harbour and Wellington), two Super 14 franchises (Blues and Chiefs), two Dunedin clubs (University and Kaikorai), two New Zealand age group sides (under-19 and colts) and an English premier club (Worcester).
That's an awful lot of team-mates, coaches, home grounds and playing strips to have had in the space of about six years.
Born in Nelson, Harding got his first real start in Otago but is now revelling in his first season with the Chiefs.
"I've been enjoying it up here. It's been quite refreshing to come into the environment,'' Harding told the Otago Daily Times from Hamilton.
"It's a really even-keeled place. Everyone gets along and there are no big egos. It's all really grounded, which is probably slightly different to some places I've been in the past.''
Harding (25) followed his older brother, former Highlanders and All Black flanker Sam, to Dunedin, and won rave reviews in his early years.
Stuck in a queue behind loose forwards Josh Blackie, Craig Newby and Alando Soakai, he transferred to Harbour, playing 12 games in 2005 before deciding to head to England at an early stage in his professional career to play for Worcester.
The club was a battler, losing 12 games in a row at one stage and spending most of a season locked in a relegation battle.
"I really enjoyed my time in England and got a lot out of it. It gave me a good perspective on rugby,'' Harding said.
"But losing so many games was a pretty tough education. Once we had a few losses we basically retreated into our forward pack and played a lot of 10-man rugby. And coming from New Zealand, I found that quite frustrating".
"I thought it would be a far more exciting prospect to come back and try to crack Super 14.''
Harding found a contract with Wellington, playing 10 games in the Air New Zealand Cup before learning he would be drafted to a Chiefs side facing its first season in nearly a decade without All Black open-side Marty Holah.
He has started two games, against the Cheetahs and the Stormers, but is competing for time with Tanerau Latimer and Hayden Hopgood.
It has been four years since Harding left Dunedin but he has close friends in the Highlanders squad and has taken no enjoyment in seeing them slump to five consecutive losses.
"They've been unlucky, with tough calls going against them, and [they've] had some narrow defeats. They've got a very good set piece but perhaps they just haven't created as many scoring opportunities as they would like.''
The Harding brothers saw each other regularly in England when Sam was playing for Northampton.
While Tom starts another phase of his career in Hamilton, Sam is playing in Italy for the Viadana club.
